1. Field of the Invention
This invention relates to automating a wrapping machine for packaging or bundling articles, typically in a thermoplastic shrinkable film.
2. Description of the Related Art
Machines for moving an article or groups of articles through the plane of a continuous film, wrapping the article or articles with the film, sealing and severing the film, and than shrinking the film around the article or articles, are exemplified by U.S. Pat. Nos. 5,046,600; 4,870,802; 4,365,456; 4,319,443; 3,739,547; 4,341,057 and 3,191,356. These patents are incorporated by reference. Basically, such machines provide a generally horizontal conveyor for moving the articles along a path. A film is vertically extended across the path of the articles from supply rolls above and below. As leading edge of the articles is moved through the plane of the film each roll rotates thereby supplying additional film that wraps the articles. As each article displaces the film a portion of the film drawn from below and another portion of the film drawn from above, cover the front and top of the article. A moving bar pulls the film from above behind the article thereby wrapping the article. After wrapping the article, the film is sealed and severed behind the article. The film is sealed across the width of the film along two spaced lines and is severed between the lines. This results in a wrapped article, which is separated from the remaining film. The remaining film is united to the upper and lower rolls by the seal so that the next article or group of articles can intercept the film. Then the wrapped article is moved through a heated tunnel to shrink the film.
Because a conveyer is used to advance the article into the plane of the wrapping film, these machines have lent themselves to automation. Pick and place machines have been used to automatically transfer the article from a feed station and a place the article directly on the conveyor.
Another method of transferring article on the conveyer has been to manually place the article directly on the wrapping film. The article is placed on the wrapping film while a portion of the film is in a substantially horizontal position to the conveyor. U.S. Pat. No. 5,619,843 shows automatically placing the article directly on a film resting on platens driven by the conveyer. The article is moved on the film by pushing the article onto the film.
These machines shown in the references or in existence are both expensive and complex. Also, where a variety of product sizes and shapes are to be packaged, a particular machine configuration may be inefficient for some of the sizes or shapes.
This invention has solved the problem in the art by producing a pick and place apparatus that is simple to operate and inexpensive to construct. The apparatus can transfer an article in at least two axis. The apparatus has the ability to manipulate the article by rotating, orienting and collating articles of various shapes and groupings. This results in a more efficient and versatile apparatus. This apparatus allows placing an article directly on the film prior to film wrapping. None of the machines in the prior art have produced a simple and inexpensive machine that automatically places the article directly on the film.